SCSI and RAID

[kontrabass]

I've currently got a webserver serving a php/mysql bulletinboard with two 15,000 RPM U320 SCSI drives, non RAID - one drive is OS & Apache, the other dedicated for MySQL databases.

Will I benefit at all by going to a RAID1 setup with two 10k RPM drives?

How about a RAID5 setup with 3 10k RPM drives?

I would save a heck of a lot of money by switching to one of these options (moving to a new datacenter)... but don't want to sacrifice performance.

Thanks!

 

[jagec]

How critical is your information?
RAID-1 will double your cost per gig. However, if you have mission-critical data, you NEED redundancy, which your current system does not have.

RAID-5 will be cheaper per gig than RAID-1, and also offers redundancy. It has slightly better read performance than RAID-1, and slightly worse write performance.

 

[Matthias99]

Originally posted by: jagec
RAID-5 will be cheaper per gig than RAID-1, and also offers redundancy. It has slightly better read performance than RAID-1, and slightly worse write performance.

Strike that, reverse it. No RAID setup can have better read performance or worse write performance than RAID1 (with the same number of disks). Think about it for a minute.

RAID5 has read performance close to RAID0, and write performance that starts out close to RAID1 (with three disks), and gets closer and closer to RAID0 as the number of disks increases (but this increases your risk of losing the array if two disks fail simultaneously).

 

[Genx87]

If your site is getting hit enough to the point where the disks are a bottleneck. Then I would suggest looking at getting a third disc and going Raid 5. This will allow you to stripe the data on two of the discs for better read performance. If you arent hit that often then Raid1 will work out just fine.